Fortified wines, those inevitable after-dinner elixirs, have been a part of the American wine industry since its inception. The early American taste for fortified wines was well documented, as the signing of the Declaration of Independence was toasted with a round of Madeira. It, along with port and sherry, was the preferred drink of the Eastern aristocracy well into our own century. That the native industry should strive to compete for this market was only natural.
As in much of the wine-producing New World, vintners took a run at sherry (and do to this day), but the results on the whole pale, often quite literally, when compared to the Spanish original. Port, however, has fared beter. While the climate and soil of Jerez has not been duplicated elsewhere, the broiling heat and winemaking practices of the Douro have proven much easier to replicate--perhaps nowhere more so than in California's Amador County and San Joaquin Valley.
Port-style wines are being made beyond California. As might be expected, a certain measure of heat helps; the most successful examples have come from warm states such as Missouri. As the saying goes, a little residual sugar can cover a multitude of sins, but the Missouri ports of producers such as Stone Hill and Mount Pleasant truly stand on their own, and have proven as consistently competent as many California versions.
Fortified refers to wines that have additional alcohol as the result of neutral spirits being added. The most common fortified wines are port and sherry, in which the alcoholic level is between 17% to 20%, higher than a standard table wine of about 13% -14.5%
Additional alcohol technically means these wines can age longer, but that period also depends on the type of wine produced, as some ports and sherries are rather light and need to be enjoyed within a few years of their release.
Given the higher percentage of alcohol, pairing these wines can be tricky, as they could overwhelm milder dishes. For port, rich cheeses, especially blue, are fine, as are walnuts. For a dry sherry, a tomato or cream soup would be an excellent match, while for a sweeter sherry, an almond tart or a simple pound cake with honey would be an excellent match. Otherwise, enjoy these wines on their own.